Abstract: A method for operating a PV system that is integrated into a power system connected to a power grid includes determining a voltage operating point for the PV system based on a maximum power point tracking (MPPT) algorithm. If an available power output of the PV system can be provided to the power grid, the method includes operating the PV system based on the voltage operating point. If the maximum available power output of the PV system cannot be provided to the power grid, the method includes applying a voltage step to the voltage operating point to drive a power output of the PV system towards an external power constraint.

Abstract: A method for operating a PV system that is integrated into a power system connected to a power grid includes determining a voltage operating point for the PV system based on a maximum power point tracking (MPPT) algorithm. If an available power output of the PV system can be provided to the power grid, the method includes operating the PV system based on the voltage operating point. If the maximum available power output of the PV system cannot be provided to the power grid, the method includes applying a voltage step to the voltage operating point to drive a power output of the PV system towards an external power constraint.

Abstract: Methods for operating a wind turbine system are provided. In one embodiment, a method includes adjusting a threshold direct current (DC) bus voltage for a dynamic brake in a wind turbine power converter above a reference DC bus voltage based on at least one system condition. The method further includes gating the dynamic brake on when an experienced DC bus voltage is equal to or greater than the threshold DC bus voltage, and inputting a dynamic brake condition into a controller when the dynamic brake is gated on. The method further includes determining if a grid fault has occurred, reducing power generation of the wind turbine if no grid fault has occurred, and blocking the power converter if a grid fault has occurred. The method further includes gating the dynamic brake off when the experienced DC bus voltage is less than the threshold DC bus voltage.

Abstract: Methods for operating a wind turbine system are provided. In one embodiment, a method includes adjusting a threshold direct current (DC) bus voltage for a dynamic brake in a wind turbine power converter above a reference DC bus voltage based on at least one system condition. The method further includes gating the dynamic brake on when an experienced DC bus voltage is equal to or greater than the threshold DC bus voltage, and inputting a dynamic brake condition into a controller when the dynamic brake is gated on. The method further includes determining if a grid fault has occurred, reducing power generation of the wind turbine if no grid fault has occurred, and blocking the power converter if a grid fault has occurred. The method further includes gating the dynamic brake off when the experienced DC bus voltage is less than the threshold DC bus voltage.

Abstract: In one aspect, a method for protecting one or more electrical machines during an islanding event is provided. The method includes connecting one or more electrical machines to an alternating current (AC) electric power system, wherein the AC electric power system is configured to transmit at least one phase of electrical power to the one or more electrical machines or to receive at least on phase of electrical power from the one or more electrical machines; electrically coupling at least a portion of a control system to at least a portion of the AC electric power system; coupling at least a portion of the control system in electronic data communication with at least a portion of the one or more electrical machines; and detecting an islanding of the one or more electrical machines based on one or more conditions monitored by the control system.